According to new research published January 18 in the scientific journal Brain, head impacts, not just concussions, may result in the degenerative brain disease called chronic traumatic encephalopathy (CTE).
This new finding could lead to early detection and improved treatment and prevention of CTE, the researchers suggest.
More than 100 National Football League players have been posthumously identified as having CTE, including former New England Patriots tight end Aaron Hernandez, who committed suicide in 2017 at the age of 27 while serving a life sentence for murder. Medical experts later said that his condition was the most severe case of CTE ever discovered in someone his age and would have affected his decision-making, judgment and cognitive abilities.
CTE has been found in the brains of teens and adults who sustained repeated head injuries, even in those who were not diagnosed with concussion, the study authors noted. The mechanisms that cause CTE, however, have been unclear.
To learn more, investigators examined brains from four teens who had suffered head injuries up to 128 days before they died. The researchers also used computer models and mice to simulate sports- and blast-related head injuries.
Researchers found that early signs of CTE not only persist long after a head injury but also spread through the brain. This provides the best evidence to date that head impact, not concussion, causes CTE, according to the authors of the study.
"To prevent the disease, you have to prevent head impact – it’s hits to the head that cause CTE," corresponding author Dr. Lee Goldstein said in a Boston University news release. “The same brain pathology that we observed in teenagers after head injury was also present in head-injured mice," Goldstein said.
"We were surprised that the brain pathology was unrelated to signs of concussion, including altered arousal and impaired balance, among others. Our findings provide strong causal evidence linking head impact to [traumatic brain injury] and early CTE, independent of concussion," he stated.
"The results may explain why approximately 20 percent of athletes with CTE never suffered a diagnosed concussion," Goldstein said.
Researchers emphasize that in order to prevent CTE among those who are at the highest risk, such as athletes and veterans, safety measures must be taken to lower the number of head injuries that occur.
The researchers suggested that the discovery that head impacts trigger CTE could lead to new ways to diagnose the disease, new treatments and better protective equipment and preventive measures.
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